1. 4-1 Three Little Words: Always, Sometimes, Never Big Idea A generalization is always true, sometimes but not always true, or never true.

2. Warm Up:

3. Background

4. Activity 1

5. Activity 2

6. Relationships between Two Sets: Two sets A and B can be related in exactly one of three ways:

7. Venn Diagrams

9. Additional Examples In 1-3, fill in the blanks with always, sometimes but not always, or never to form a true statement. 1. People __________ turn younger as they age. 2. Cell phones _________ have cameras. 3. The sun ________ sets in the west. never Sometimes but Not always always

10. In 4-6, determine whether the statement is true or false. If false, give a counterexample. 4. All salmon are fish. _____________ 5. All polygons are squares. _________ 6. All 4-legged animals are cats. ______ 7. Draw a venn diagram representing this situation: 12 students in all went to the zoo, 19 students in all went to the museum, but 7 students went to both.